package org.viva.core.util;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class GenericsUtils {
	private final Log	logger	= LogFactory.getLog(GenericsUtils.class);

	protected GenericsUtils() {}

	public Class<?> getSuperClassGenricType(Class<?> clazz) {
		return getSuperClassGenricType(clazz, 0);
	}

	public Class<?> getSuperClassGenricType(Class<?> clazz, int index) {
		Type genType = clazz.getGenericSuperclass();

		if (!(genType instanceof ParameterizedType)) {
			logger.warn(clazz.getSimpleName() + "'s superclass not ParameterizedType");

			return Object.class;
		}

		Type[] params = ((ParameterizedType) genType).getActualTypeArguments();

		if ((index >= params.length) || (index < 0)) {
			logger.warn("Index: " + index + ", Size of " + clazz.getSimpleName() + "'s Parameterized Type: " + params.length);

			return Object.class;
		}

		if (!(params[index] instanceof Class<?>)) {
			logger.warn(clazz.getSimpleName() + " not set the actual class on superclass generic parameter");

			return Object.class;
		}

		return (Class<?>) params[index];
	}
}
